Re: Microsoft and the two great blunders

Costin Cozianu <c_cozianu_at_hotmail.com> wrote in message news:<bsavog$bg13t$1_at_ID-152540.news.uni-berlin.de>...

> Well, if you want to hold to the relational orthodoxy, you ought to call
> those relvar. But to make it clear we'll call them table, shall we ?

I don't see anything clearer in table. Table value or table variable?

> Now let's further consider that the table EMPLOYEE stores all the tuples
> that have the type EMPLOYEE%ROWTYPE (using SQL terms, i.e. the type of
> the tuples).

Tuples have a tuple type, scalars have a scalar type. If you want to represent a scalar value with a tuple value you need a type redesign. You may use a monadic tuple or an n-adic tuple.

> I'm waiting for someone to make the case why would that be such a big deal ?

It is not a big deal.

> Quite nice. But according to D&D types are sets of values. Well, then a
> relation is a set of value.

According to D&D and many other people, types can be viewed as sets of values associated to sets of operators. On the other hand, a relation is an individual constant. But the "great blunder" is to confuse types with relation variables, not whith relations (values). Another common mistake is to confuse values with variables all the time.

>
> According to proper type theory, a type is much more, of course.

According to D&D too.

> For lack of better things to do, people think that if they throw
> Microsoft and a couple of relational orthodoxy together, they've got a
> valid point.

It is not only against relational correction, it is against most fundamental data management principles.

The "Persistence Layer" approach leads to manage data in the applications using network structures, to move from declarative code to procedural code and to use DBMSes as mere file managers.

That's the big deal. It is a return to the stone age.

Microsoft kept away from this nonsense until now, that was reason because I posted the link.

Regards
  Alfredo Received on Wed Dec 24 2003 - 13:38:44 CET